Not Applicable
1. Field of Invention
This invention pertains to a method of producing a scintillator detector arrays that may be used in various applications, such as, but not limited to, a PET detector module or nuclear physics applications. More specifically, it relates to a method of producing a high resolution detector array that can be coupled to photodetectors. In certain applications, the photodetector provides an accurate timing pulse and initial energy discrimination, identification of the crystal interaction, which may include the depth of interaction (DOI).
2. Description of the Related Art
When constructing scintillator arrays, it is known to use block scintillator arrays with sawcut grooves packed with reflector powder. However, this method is not feasible for producing arrays of individual crystals. It is also known to use reflector molds made of a white compound. However, it is often desired to produce light output with a greater depth dependence than these type of reflectors are capable of producing.
Finally, it is also known to hand wrap xe2x80x9cplumbersxe2x80x9d Teflon(copyright) tape around individual detectors as a standard reflector choice for research PET cameras. However, plumbers Teflon(copyright) tape is not a realistic choice for large cameras and/or cameras that use very small crystals. Further, hand wrapping individual crystals is both time consuming and difficult to do consistently. Hand wrapping with Teflon(copyright) tape also limits the reduction of crystal size for future cameras. In addition, plumbers Teflon(copyright) tape, or thicker 8 mil Teflon(copyright) tape, is not an ideal reflector. It stretches and creeps, so it can be difficult to accurately cover only the surface of each crystal not coupled to a photodetector. The Teflon(copyright) tape also becomes transparent when squeezed, which occurs when making a compact scintillator crystal array, and when glue wicks through it. Moreover, it is difficult to wrap the individual crystals tightly with thicker 8 mil Teflon(copyright) tape resulting in inaccurate measures of depth dependence.
What is missing from the art is a method of disposing a reflector between each individual crystal of a high resolution detector array which can efficiently, consistently and accurately cover the desired surfaces of an individual crystal. Accordingly, it is an object of the present invention to provide a method of producing a high resolution detector array having a reflector disposed between individual crystals of the array.
It is a further object of the present invention is to provide a method for producing a high resolution detector array efficiently, consistently and accurately covers the desired surfaces of an individual crystal.
Yet another the object of the present invention is to provide a method for producing a high resolution detector array which will provide very high packing fraction i.e. the distance between scintillator elements will be minimized so the detector efficiency will be higher than is currently achievable.
Still another object of the present invention is to provide a method for producing a high resolution detector array which eliminates the need to hand wrap individual crystals.
In one embodiment of the present invention, the fabrication methodology is enhanced by handling LSO bars rather than single crystals when gluing on the Lumirror(copyright) as well as etching the LSO. Namely, an LSO boule is cut into bars of a selected dimension, for example 30 mm wide, which are then acid etched. A selected number, N, of these LSO bars can then be glued together with Lumirror(copyright) sheets between each bar (coating the LSO bars and Lumirror(copyright) sheets with Epotek 301-2). The glued bar block is then cut again into bars in a perpendicular direction, and these new LSO-Lumirror(copyright) bars are etched. Finally, a selected number, M, of these LSO-Lumirror(copyright) bars are glued together with Lumirror(copyright) sheets between each bar; thus creating an etched Nxc3x97M LSO-Lumirror(copyright) array without having to handle individual LSO crystals or small Lumirror(copyright) pieces It will be appreciated by those skilled in the art that while M may be equal to N, M can also be greater than or less than N.